Reversible edge bit structure for blade of earth working implement



Sept. 30, 1969 J. J. wooo 3,459,331

REVERSIBLE EDGE BIT STRUCTURE FOR BLADE 0F EARTH WORKING IMPLEMENT Filed Oct. 21, 1965 F IG- IE.

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United States Patent US. Cl. 37-441 3 Claims ABSTRACT OF THE DISCLOSURE A mounting plate is mounted along the working edge of the mold board of an earth working implement such as a bulldozer, the mounting plate having a plurality of notches at selected spaced intervals in the edge thereof toward the working edge of the mold board. The edges of the notches are undercut, and the mounting plate has a plurality of holes therein for receiving anchor pins. A plurality of edge bits are provided for mounting in either of two relatively reversed, aligned positions along the mounting plate. Each bit has a plurality of marginally undercut keys projecting from the rear face thereof and spaced to enter, and to fit into and in interlocking engagement with the notches in the mounting plate in either of two relatively reversed positions of the bits. Holes are provided in each bit in position to register with the anchor pin holes in the mounting plate in either of the two relatively reversed positions of each bit, and anchor pins are inserted into the registering holes to retain the bits with the keys fully inserted in their respective notches.

PRIOR ART Structures providing wear absorbing mold board bits are shown in my Patent No. 3,152,411, issued Oct. 13, 1964, and application Ser. No. 472,848 filed July 19, 1965 and now abandoned.

An object of the invention is to provide a replaceable, reversible edge bit structure for mounting on the working edge of the mold board of a scraper type earth working implement by securing a mounting plate having a marginally undercut notch therein to the working face of a mold board adjacent the working edge thereof, and fitting a replaceable edge bit member having a marginally undercut key on the rear face thereof into relatively interlocking relation with the marginally undercut notch of the mounting plate in either of two relatively reversed positions.

Another object of the invention is to provide an improved, reversible, replaceable edge bit structure for mounting along the working edge of the mold board of a scraper type earth working implement.

, Another object of the invention is to provide a boltless, reversible edge bit member for interlocking engagement with a support plate.

The foregoing objects and advantages of the invention will be apparent from the following description and the accompanying drawings wherein:

FIG. 1 is a fragmentary, end, elevational view of the lower portion of the mold board of a scraper type earth working implement with a replaceable, reversible edge bit structure embodying the invention mounted thereon.

FIG. 2 is a fragmentary, rear elevational view looking in the direction of the arrows 2-2 of FIG. 1, a portion of the mold board being broken away.

FIG. 3 is a fragmentary, sectional view taken along line 3-3 of FIG. 2.

FIG. 4 is an exploded view showing the elements of FIG. 1 displaced in the direction of the arrows of FIG. 4.

FIG. 5 is an enlarged, perspective view of one of the hooks before welding to a mounting plate.

FIG. 6 is a rear elevational view in reduced scale of a replaceable, reversible edge bit member, the solid lines showing one form thereof, and the broken lines showing an alternate form thereof.

FIG. 7 is a similar rear elevational view of a mounting plate for use with the bit of FIG. 6.

FIG. 8 is a rear elevational view in further reduced scale showing two of the mounting plates of FIG. 7 in the position they would occupy when mounted along the working edge portion of a mold board, the broken lines showing an alternate form thereof.

FIGS. 9 and 10 are rear elevational views generally similar to those of FIGS. 6 and 7, but drawn to the same scale as FIG. 8, and showing a mounting plate and edge bit member with rectangular notches and interlocking keys.

Referring to the drawings in detail, a mold board A may be that of any scraper type earth working implement, such as, for example, a conventional road scraper or grader, or a bulldozer. In the replaceable, reversible edge bit structure B of the present invention as shown in FIGS. 1-8, a plurality of mounting plates 10 are mounted along the forward or working face of the mold board A, with the lower edge of each mounting plate 10 substantially aligned with the working edge of the mold board.

Considering first only the form of mounting plate 10 shown in solid lines in FIGS. 7 and 8, a plurality of hooks 11 (FIG. 5) preferably are welded, one in each of a plurality of shallow notches 12 provided in the lower edge of each mounting plate 10. These hooks are shaped to engage a rearward portion of the mold board to resist stresses which would tend to force the mounting plates edgewise away from the working edge of the mold board or to pull the mounting plates 10 away from the mold board A. As shown in FIGS. 7 and 8, a hook receiving notch 12 is provided on the right-hand end of each mounting plate 10, and the other end thereof is correspondingly shortened, so that when a plurality of the mounting plates 10 are mounted along the working edge of a mold board as shown in FIG. 8, the hook receiving notches 12 will be symmetrically spaced throughout the entire length of the assembly.

A plurality of key receiving notches 13 are also provided in the lower edge of each mounting plate 10, and extend upwardly therein preferably throughout a substantial portion of the width of the mounting plate. The marginal edges 14 of each key receiving notch 13 are beveled on the rear or mold-board-facing side of the mounting plate 10, so that when the mounting plates are mounted in aligned relation along the working edge of a mold board A with the bevels facing the mold board, the marginal portions of these notches will be undercut by means of the beveled edges of the notches. Each mounting plate 10 has a plurality of countersunk holes 15 therein to receive countersunk head type bolts 17 for bolting the mounting plates to the mold board.

When the hooks 11 are provided on the mounting plates, they are mounted in hooked engagement with the working edge of the mold board 10.

The mounting plates and the reversible, replaceable edge bit members 18 preferably are all made from high grade cast steel, and are individually designed to fit various mold boards for which they are sold. In order to provide some flexibility of design, the mounting plates 10 and edge bit members 18 can be extended on their lefthand ends and shortened on their right-hand ends as indicated in broken lines in FIGS. 7 and 8. Such variations can be readily accomplished by providing replaceable end portions for the patterns from which these members are made, as will be obvious to anyone familiar with metal molding and pattern making practices, and since the details thereof are not a feature of the present invention it will be unnecessary to explain them herein.

Each replaceable edge bit member 18 comprises a plate portion 19 with one or more, preferably a plurality of marginally undercut keys 20 cast integrally on the rear or mold-board-facing side thereof. The keys 20 are shaped and positioned, and the edges 20' thereof are undercut for fitting into marginally interlocking engagement with the beveled, undercut edges 14 of the key notches 13 in the mounting plates 10.

Four holes 21 are provided in each bit member 18, and these holes are so located that two thereof will register with two holes 22 in an associated mounting plate 10 when the bit member 18 is mounted thereon with the keys 20 thereof fitted in relatively interlocking relation into the key notches 13 thereof as shown in FIGS. 1 and 2.

Two roll pins 23 of a well-known type are driven, one into each registering pair of holes 21 and 22 of an edge bit member 18 and its associated mounting plate 10 to firmly anchor the edge bit members 18 against slidable, edgewise displacement relative to their mounting plates.

In the modified form of the invention shown in FIGS. 9 and 10, rectangular, marginally undercut notches 13a are providing in the mounting plates 10a and receive an interlocking relation therein correspondingly shaped, marginally undercut rectangular keys 20a on the replaceable, reversible bits 18a. An advantage of this modified structure resides in the fact that the rectangular keys 20a have interlocking engagement with the undercut beveled edges of the rectangular key notches 13a of their mounting plates 10a throughout the entire depth of the notches. The disadvantage is that they are more difficult to replace than the form shown in FIGS. 2, 6 and 7, wherein the angularly diverging beveled portions 13' adjacent the open end of each notch, and the angularly diverging beveled portions 13" adjacent the closed end of each notch facilitate removal of the keys 20 (FIG. 6) therefrom.

In using the invention as shown in FIGS. 1-8, a plurality of the mounting plates 10 are mounted on the working face, and along the working edge of a mold board A of an earth working implement. Using the countersunk holes 15 in the mounting plate 10 as guides, holes are drilled through the mold board, and countersunk head bolts 17 are fitted into the registering holes in the mounting plates 10 and those drilled in the mold board A. These bolts 17 are drawn down tight to firmly and securely anchor the mounting plates 10 to the mold board A. The mounting plates 10 when thus mounted may be considered part of the mold board and can, if desired, be welded to the mold board, in which case the hooks 11 may be eliminated. These books 11 also may be eliminated if the working edge of the mold board is not apt to be subjected to severe reverse stresses which would tend to pull the mounting plates from the mold board.

The bits 18 are then fitted into position, the undercut keys 20 of each being forced firmly home into corresponding notches 13 in the mounting plates. Using the uppermost pair of holes 21 in each bit member 19 when thus fitted securely into interlocking relation with its respective mounting plate 10, and the holes 22 in the mounting plate 10 in register therewith as guides, a hole is then drilled through the mold board and the roll pins 23 are driven therein through the registering holes 21 and 22.

The implement is then ready for use, and is used in a customary manner under the bits 18 are worn down to a condition wherein their exposed edges are substantially flush with the working edge of the mold board 10. The roll pins 23 are then driven out, the bits 18 reversed edge-for-edge, or replaced by new ones, and the keys 20 again set home in their reversed condition in the notches 13. Roll pins 23 are then again driven into position as shown in FIGS. 1 and 2, whereupon the implement is ready for use. Thus, for each set of edge bits 18, two complete working edge portions are provided, thereby in effect doubling the life of the bits.

A great advantage in this construction, in addition to the reversible nature of the edge bits, resides in its boltless nature. The rolls pins can be driven out with a hammer and any convenient bar, pipe or other object used as a drift, so that the bits can be quickly reversed or changed right on the job, and by the implements operator himself in an emergency.

The invention provides a simple, rugged, economical protection for the Working edge portions of the mold boards of scraper type earth Working equipment. The bit structure B can be quickly and easily mounted on any scraper type mold board for which they are designed, and while the original installation including the securing of the mounting plates requires a few hours, thereafter the reversal of the bits, or their replacement by new ones, when both edges are completely worn away, is a simple, quick operation which can be performed in the field and without the necessity of any shop equipment. The plate portion of each bit covers and protects the mounting plate with which it is interlockingly engaged, so that the mounting plates last indefinitely.

While I have illustrated and described a preferred embodiment of the present invention, it will be understood, however, that various changes and modifications may be made in the details thereof without departing from the scope of the invention.

I claim:

1. A replaceable, reversible edge bit structure for mounting on the mold board of a scraper type earth 0 working implement comprising:

a mounting plate, having a plurality of holes therein for receiving anchor pins,

means for securing the mounting plate on the mold board with the lower edge thereof along the working edge of the mold board, the mounting plate having a plurality of marginally undercut key receiving notches in the edge thereof along the working edge of the mold board,

a plurality of reversible edges bit members, each comprising a plate portion and a plurality of keys projecting from the rear face thereof, each key being marginally undercut, and shaped and positioned for endwise, close, interfitted, interlocking insertion in one of the notches in the mounting plates,

the keys being shaped on both ends thereof for fitted insertion in the key receiving notches with the edge bit members in either of two end-for-end reversed conditions, the plate portion of each edge bit member extending beyond both ends of the keys to provide a projecting working edge portion with the keys inserted in the notches with the edge bit members in either of their relatively reversed conditions, the plate portion of each edge bit member having a hole therein positioned to register with each of the anchor pin holes in the mounting plate with the keys fully inserted in the notches with the edge bit members in either of their relatively reversed positions, and

a plurality of anchor pins, for fitted insertion in the registering holes of the mounting plate and the edge bit members to retain the keys fully inserted in their References Cited respective notches in each of the relatively reversed UNITED STATES PATENTS POSltlOl'lS of the edge bit members.

2. A replaceable, reversible edge bit member as claimed 989,729 4/1911 Swmdle 172753 X in claim 1 wherein a hook is provided on the edge of 5 1,168,469 1/1916 BePson 172-703 each mounting plate positioned along the working edge 2,310,396 2/1943 01914563165- of the mold board, the hook being shaped and positioned 219651989 12/1960 Hlbbal'dto engage a rearwardly directed surface portion of the mold board to resist forces tending to pull the mounting ANTONIO GUIDA Pnmary Exammer plate away from the mold board. 10 ALAN E. KOPECKI, Assistant Examiner 3. An edge bit structure as claimed in claim 1 wherein the pin fitted into each set of registering holes is a roll US. Cl. X.R.

pin of rolled, springy sheet metal. 172-704, 719 

